Combination square



Feb. 22,1927. 4 l 1,618,862

` lFe. K. COLLINS COMBINATION SQUARE Filed M arch l0. 1924 ahjfzvazzzf@ Patented Feb. 22, 1927.

A,ParisNT oFFlcE.

ROBERT K. COLLINS, OF CANTON, NORTH CAROLINA.

COMBINATION SQUARE.

Application filed March'lO, 1924. Serial No. 698,119.

The object of the invention is to provide a tool particularly adapted for laying off and 'finding the right lengths of 4the various kind of rafters encountered in roofs ofpitched construction, so that the various lengths may be readily determined from the indicated difference between the rafters.

lViththis object in View the invention consists in a construction and combination of parts of which a preferred embodiment is shown in the accompanying drawings, wherein Figure l is a plan view of the invention.

Figure 2 is a sectional view on the line 2 2 of Figure l.

The invention comprises the. main and supplemental squares l and 2 and a plurality of blades 3 preferably of varying lengths as indicated at 3a, 3') and 3. The square l on one edge of one of its arms is provided with graduations l preferably in si'Xteenths and on the other edge with graduations Ypreferably in twelfths of an inch, t-he supplemental square being similarly divided as indicated at 6 and respectively. wSimilar divisions are also made on the blades 3, 3b and 3c as indicated generally at 8 and 9.

Both arms of the main square 1 are slotted longitudinally as indicated at l() and the supplemental square also slotted indi catedv at 1l, likewise the blades are formed with longitudinal slots l2. Preferably the slots 10, l1 and 12 are formed with inclined side walls as indicated at 13 in Figure 2 to make them cross-sectionally trapezoidal for the reception of flat head screw bolts 14 the shanks of which pass through the slots of connected members as indicated in Figure l. and receive the hand screws 15 by which angular positions at which it is desired to dispose the different elements may be maintained.

The length of the common rafters is found by laying off on one leg of the square l the span of the roof and then laying olf on the other leg the height of the hip above the wall plates. The one leg of the supplemental square is then disposed diagonally across these points and the length indicated on its edge is the length of the common rafter. The lengths of the hip rafters are then determined by the blade 3c' by laying off on the other leg of the supplemental square a distance equal to the span of the` hip rafter in a horizontal plane. Securing the blade 3 at this Apoint on the leg of the supplemental square and connecting it with the point ofconnection between the supplemental square and the main square will indicate on the blade 3C the length of the hip rafter, or the Valley rafter if it is the length of the latter that is sought. The jack rafters are then found by disposing the blades 3a and 3b at specified distances on the short leg of the supplemental square between the point of connection of the leg with the main square and t-he point of connection with the blade 3C, the blades 3a and 3b being disposed parallel with that leg of the supplemental square which spans the legs of the main square. lVhere these blades 3a and 3b crossfthe blade 3, the lengths of the different jack rafters will be indicated.

laving described the invention, what is claimed as new and useful is A combination tool comprising main and supplemental squares .and a plurality of' blades, means for connecting the squares with the longer yleg of the supplemental square in spanning relation with the angle of the main square, and means for clamping one of the blades in spanning relation with the angle of the supplemental square and the remaining blades 4in parallelism withV the longer leg of the supplemental square and in corresponding relation with the .'irst said blade, vthe legs of both squares being lslotted longitudinally and the blades being provided with longitudinal slots, the clamping means consistinG-'of bolts aassin throuffh said slots to provide for relative adjiistment of the several elements.

In testimony whereof he aiiixcs his signature.

ROBERT K. COLLINS. 

